About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
High-Entropy Materials: Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond VI
|
| Presentation Title |
Assessing Thin Films as Predictors of Bulk Properties in High-Throughput Alloy Design |
| Author(s) |
Janith C. Wanni, Chanho Lee, Deva Prasad Neelakandan, Benjamin Kyle Derby, Osman El Atwani, James A. Valdez, Michael C Gao, Mikayla Alexa Obrist, Gaskey Daniel Bernard, Nan Li, Saryu J. Fensin |
| On-Site Speaker (Planned) |
Janith C. Wanni |
| Abstract Scope |
Thin-film deposition enables rapid alloy screening, but its ability to predict bulk behavior remains unclear. In this study, we compare the microstructure and mechanical properties of thin-film and bulk forms of a five-element NbMoTaTiV refractory high-entropy alloy. Fifteen thin-film compositions were fabricated using magnetron sputtering, while five representative compositions were synthesized in bulk via arc melting. Both formats exhibited a single-phase BCC structure, indicating that thin films can reliably capture phase formation. Despite this similarity, pronounced differences in microstructure and chemistry were observed. The thin films had ultrafine columnar grains (~100 nm) with micron-scale chemical uniformity, whereas bulk alloys exhibited coarse equiaxed grains (~100–150 μm) and persistent elemental segregation even after high-temperature annealing. While nanohardness trends in thin films broadly aligned with bulk nanoindentation and Vickers hardness, compressive testing revealed that hardness alone is insufficient to predict yield strength. Therefore, bulk validation remains essential. |